As is known, internal combustion engines are utilized in a wide variety of applications, including stand-by electrical generators. It can be appreciated that the number of small internal combustion engines has risen dramatically over the past few years. As a result, state and federal regulators have begun to develop certain regulatory standards to insure that any air pollution generated by these types of engines is minimized.
One way to limit pollution, while simultaneously maximizing the efficiency of the engine, is to feed fuel to the engine within a predetermined range of rates. When an engine is fueled by a single liquid or gas fuel having a known, standard energy content per unit of fuel measure, e.g., British Thermal Units (BTU) per pound, it is a relatively straight forward process to configure a valve to flow fuel from a source to the engine at a particular rate. However, the task is significantly more complex when an engine has the ability to be fueled with either of two fuels, such as natural gas or liquefied propane vapor. More specifically, since the standard energy content of the two fuels is different, when fueling a small engine, it is necessary to be able to adjust the fuel flow rate in order to maximize the efficiency of the engine while maintaining the pollution generated by the engine below predetermined regulatory standards.
In order to adjust the fuel flow rate provided to the internal combustion engine, prior dual fuel valves have been developed. By way of example, Hayworth et al., U.S. Pat. No. 6,068,017 discloses a valve for flowing gaseous fuel, such as natural gas or propane vapor, to an internal combustion engine. The valve includes a valve body having an inlet passage, and first and second outlet passages in full communication with the inlet passage. A plug-type adjustment member is threaded into the body and an annular seat in the body co-acts with the adjustment member to form an orifice in the first outlet path. A stop mechanism limits movement of the adjustment member between a first position in which the orifice is smaller than a second position in which the orifice is larger. The valve permits the adjustment of the fuel flow to small engines so that such engines provide maximum power without exceeding applicable admission standards.
While functional for its intended purpose, the process for converting the valve between the dual fuels is a manual process and is somewhat time consuming. More specifically, the use of the dual fuel valve disclosed in the '017 patent requires the repositioning of hoses, the threading of a jet or orifice device into or out of the valve body, regulation of the jet and additional adjustments. Consequently, it is highly desirable to provide a fuel selection device that is simple to utilize and more user friendly than prior dual fuel valves.
It is a primary object and feature of the present invention to provide a fuel selection device that allows a user to configure the internal combustion engine to receive the flow of one of a plurality of different fuels.
It is a further object and feature of the present invention to provide a fuel selection device that allows a user to configure the internal combustion engine to receive the flow of one of a plurality of different fuels within predetermined standards.
It is a still further object and feature of the present invention to provide a fuel selection device that allows a user to configure the internal combustion engine to receive the flow of one of a plurality of different fuels and that is simple to use.
In accordance with the present invention, a fuel selection device is provided for allowing a user to select a flow path for fuel to be provided to an engine. The fuel selection device includes a first input conduit having a first end connectable to a user selected fuel source for receiving fuel therefrom and a second end. A selector switch has an input communicating with the second end of the first input conduit and an output. The selector switch is movable between a first position wherein the input and output of the selector switch communicate through a first flow path and a second position wherein the input and output of the selector switch communicate through a second flow path.
The selector switch includes a housing having a movable selector therein. The selector defines the first and second flow paths. The selector extends along a longitudinal axis and is axially movable between the first and second positions. It is contemplated for the fuel selection device to include a second input conduit having a first end connectable to the user selected fuel source for receiving fuel therefrom and a second end. The selector switch includes a second input communicating with the second end of the second input conduit and a second output. In addition, the selector switch includes third and fourth flow paths. The second input and the second output of the selector switch communicate through the third flow path with the selector switch in the first position. In addition, the second input and the second output of the selector switch communicate through the fourth flow path with the selector switch in the second position. The first flow path is generally cylindrical and has a diameter. Similarly, the second flow path is generally cylindrical and has a diameter. The diameter of the first flow path being different than the diameter of the second flow path.
In accordance with a further aspect of the present invention, an improvement in a engine fueled by a plurality of fuels is provided. The engine has first and second cylinders. The improvement includes a selection device having first and second inputs operatively connected to a fuel source. A first output is operatively connectable to the first cylinder of the engine. A second output is operatively connectable to the second cylinder of the engine. The selection device is movable between first and second positions. In the first position, the first input and the first output of the selection device communicate through a first flow path, and the second input and the second output of the selection device communicate through a second flow path. In the second position, the first input and the first output of the selection device communicate through a third flow path, and the second input and the second output of the selection device communicate through a fourth flow path
The selection device includes a housing extending along an axis. The housing has an inner surface defining a cavity therein. A movable selector is positioned within the cavity in the housing. The selector defines the first, second, third and fourth flow paths. The selector extends along the axis and is axially movable between the first and second positions. The housing defines a first closed end of the cavity and a second open end. The selector includes first and second opposite ends. The first end of the selector engages the closed end of the cavity with the selector in the first position. A stop may be interconnected to the housing. The second end of the selector may include a shoulder formed therein that engages the stop with the selector in the second position.
The improvement may also include first and second input conduits. The first input conduit has a first end connectable to the user selected fuel source for receiving fuel therefrom and a second end operatively connected to the first input. The second input conduit has a first end connectable to the user selected fuel source for receiving fuel therefrom and a second end operatively connected to the second input.
The selection device may also include a third input and a third output. The third input communicates with the third output through a fifth flow path with the selection device in the first position. Alternatively, the third input is isolated from the third output with the selection device in the second position.
In accordance with a still further aspect of the present invention, a fuel selection device is provided for allowing a user to connect a first cylinder of an engine to a user-selected fuel source. The fuel selection device includes a housing defining a cavity and a selector receivable in the cavity. The selector defines first and second flow paths. In addition, the selector is movable between a first position wherein the first cylinder communicates with the first flow path and a second position wherein the first cylinder communicates with the second flow path.
The housing includes a first input connectable to the fuel source and a first output operatively connectable to the first cylinder. The first input and the first output communicate with the first flow path with the selector in the first position and communicate with the second flow path with the selector in the second position. The housing also includes an inner surface that defines the cavity and the selector includes an outer surface that forms a slidable interface with the inner surface of the housing. A first seal extends about the outer surface of the selector between the first flow path and an end of the selector. The fuel selection device may also include first and second stops. The selector engages the first stop with the selector in the first position and the selector engages the second stop with the selector in the second position.